MariaDB never supported this form of preemption via high-priority
transactions. This error code shold not have been added in the
first place, in commit 2e814d4702.
fts_cache_t::total_size_at_sync: New field, to sample total_size.
fts_add_doc_by_id(): Invoke sync if total_size has grown too much
since the previous sync request. (Maintain cache->total_size_at_sync.)
ib_wqueue_t::length: Caches ib_list_len(*items).
ib_wqueue_len(): Removed. We will refer to fts_optimize_wq->length
directly.
Based on mysql/mysql-server@bc9c46bf28
Between btr_pcur_store_position() and btr_pcur_restore_position()
it is possible that purge empties a table and enlarges
index->n_core_fields and index->n_core_null_bytes.
Therefore, we must cache index->n_core_fields in
btr_pcur_t::old_n_core_fields so that btr_pcur_t::old_rec can be
parsed correctly.
Unfortunately, this is a huge change, because we will replace
"bool leaf" parameters with "ulint n_core"
(passing index->n_core_fields, or 0 for non-leaf pages).
For special cases where we know that index->is_instant() cannot hold,
we may also pass index->n_fields.
First part (row0mysql.cc) fixes ins_node_set_new_row() usage workflow
as it is designed to operate on empty row (see row_get_prebuilt_insert_row()
for example).
Second part (row0ins.cc) fixes duplicate key error in FTS_DOC_ID_INDEX
since history rows must not generate entries in that index. We detect
FTS_DOC_ID_INDEX by a number of attributes and skip it if the row is
historical.
Misc fixes:
row_build_index_entry_low() does not accept non-NULL tuple
for FTS index (subject assertion fails), assertion (index->type !=
DICT_FTS) adds code understanding.
Now as historical_row is copied in row_update_vers_insert() there is
no need to copy the row twice: ROW_COPY_POINTERS is used to build
historical_row initially.
dbug_print_rec() debug functions.
LATCH_ID_OS_AIO_READ_MUTEX,
LATCH_ID_OS_AIO_WRITE_MUTEX,
LATCH_ID_OS_AIO_LOG_MUTEX,
LATCH_ID_OS_AIO_IBUF_MUTEX,
LATCH_ID_OS_AIO_SYNC_MUTEX: Remove. The tpool is not instrumented.
lock_set_timeout_event(): Remove.
srv_sys_mutex_key, srv_sys_t::mutex, SYNC_THREADS: Remove.
srv_slot_t::suspended: Remove. We only ever assigned this data member
true, so it is redundant.
ib_wqueue_wait(), ib_wqueue_timedwait(): Remove.
os_thread_join(): Remove.
os_thread_create(), os_thread_exit(): Remove redundant parameters.
These were missed in commit 5e62b6a5e0.
Add CRC32C code to mysys. The x86-64 implementation uses PCMULQDQ in addition to CRC32 instruction
after Intel whitepaper, and is ported from rocksdb code.
Optimized ARM and POWER CRC32 were already present in mysys.
Removed some inine assembly, replaced by code from
https://github.com/intel/soft-crc
Also,replace GCC inline assembly for cpuid in ut0crc32 with __cpuid,
to fix "PIC register clobbered by 'ebx' in 'asm'.
This enables fast CRC32C on 32bit Intel processors with GCC.
In commit 94d0bb4dbe (MDEV-20377)
we replaced some inline assembler code with calls to GCC-style
builtin functions. These functions would only be available if
the target allows SSE4.2 instructions to be used. Hence, the
cmake -DWITH_MSAN=ON build would fail unless the default x86 (IA-32)
or AMD64 target was overridden.
It turns out that the problem can be solved by overriding the default
target architecture for specific functions with the help of GCC function
attributes.
ut_crc32c_8(), ut_crc32c_64(): Use the compiler-builtin intrinsic
functions. For GCC before 5, the header file <nmmintrin.h> does not
really work, and we must keep using the compiler built-in functions.
For the Microsoft compiler, we will keep using <intrin.h> because
we will also need the definition of the __cpuid() function.
On GCC and clang, we prefer to invoke inline assembler for that.
Curiously, the inline assembler in has_sse4_2() or crc32_pclmul()
is not causing any trouble for MSAN. Also, the inline assembler
in WolfSSL appears to be fine now. Something might have changed
between clang-8 and clang-10 (10.0.1).
When MDEV-22669 introduced CRC-32C acceleration to IA-32,
it worked around a compiler bug by disabling the acceleration
on GCC 4 for IA-32 altogether, even though the compiler bug
only affects -fPIC builds that are targeting IA-32.
Let us extend the solution fe5dbfe723
and define HAVE_CPUID_INSTRUCTION that allows us to implement
a necessary and sufficient work-around of the compiler bug.
Raspberry Pi 4 supports crc32 but doesn't support pmull (MDEV-23030).
The PR #1645 offers a solution to fix this issue. But it does not consider
the condition that the target platform does support crc32 but not support PMULL.
In this condition, it should leverage the Arm64 crc32 instruction (__crc32c) and
just only skip parallel computation (pmull/vmull) rather than skip all hardware
crc32 instruction of computation.
The PR also removes unnecessary CRC32_ZERO branch in 'crc32c_aarch64' for MariaDB,
formats the indent and coding style.
Change-Id: I76371a6bd767b4985600e8cca10983d71b7e9459
Signed-off-by: Yuqi Gu <yuqi.gu@arm.com>
MariaDB adopted a hardware optimized crc32c approach on ARM64 starting 10.5.
Said implementation of crc32c needs support from target hardware for crc32
and pmull instructions. Existing logic is checking only for crc32 support
from target hardware through a runtime check and so if target hardware
doesn't support pmull it would cause things to fail/crash.
Expanded runtime check to ensure pmull support is also checked on the target
hardware along with existing crc32.
Thanks to Marko and Daniel for review.
MemorySanitizer (clang -fsanitize=memory) requires that all code
be compiled with instrumentation enabled. The only exception is the
C runtime library. Failure to use instrumented libraries will cause
bogus messages about memory being uninitialized.
In WITH_MSAN builds, we must avoid calling getservbyname(),
because even though it is a standard library function, it is
not instrumented, not even in clang 10.
Note: Before MariaDB Server 10.5, ./mtr will typically fail
due to the old PCRE library, which was updated in MDEV-14024.
The following cmake options were tested on 10.5
in commit 94d0bb4dbe:
cmake \
-DCMAKE_C_FLAGS='-march=native -O2' \
-DCMAKE_CXX_FLAGS='-stdlib=libc++ -march=native -O2' \
-DWITH_EMBEDDED_SERVER=OFF -DWITH_UNIT_TESTS=OFF -DCMAKE_BUILD_TYPE=Debug \
-DWITH_INNODB_{BZIP2,LZ4,LZMA,LZO,SNAPPY}=OFF \
-DPLUGIN_{ARCHIVE,TOKUDB,MROONGA,OQGRAPH,ROCKSDB,CONNECT,SPIDER}=NO \
-DWITH_SAFEMALLOC=OFF \
-DWITH_{ZLIB,SSL,PCRE}=bundled \
-DHAVE_LIBAIO_H=0 \
-DWITH_MSAN=ON
MEM_MAKE_DEFINED(): An alias for VALGRIND_MAKE_MEM_DEFINED()
and __msan_unpoison().
MEM_GET_VBITS(), MEM_SET_VBITS(): Aliases for
VALGRIND_GET_VBITS(), VALGRIND_SET_VBITS(), __msan_copy_shadow().
InnoDB: Replace the UNIV_MEM_ macros with corresponding MEM_ macros.
ut_crc32_8_hw(), ut_crc32_64_low_hw(): Use the compiler built-in
functions instead of inline assembler when building WITH_MSAN.
This will require at least -msse4.2 when building for IA-32 or AMD64.
The inline assembler would not be instrumented, and would thus cause
bogus failures.
Change how lookup for the "auto" PSI_memory_keys is done.
Lookup for filename hashes (integers), instead of C strings
Generate these hashes at the compile time with constexpr,
rather than at runtime.
User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE
and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0
and will no longer report the PAGE_STATE value READY_FOR_USE.
We will remove some fields from buf_page_t and move much code to
member functions of buf_pool_t and buf_page_t, so that the access
rules of data members can be enforced consistently.
Evicting or adding pages in buf_pool.LRU will remain covered by
buf_pool.mutex.
Evicting or adding pages in buf_pool.page_hash will remain
covered by both buf_pool.mutex and the buf_pool.page_hash X-latch.
After this fix, buf_pool.page_hash lookups can entirely
avoid acquiring buf_pool.mutex, only relying on
buf_pool.hash_lock_get() S-latch.
Similarly, buf_flush_check_neighbors() can will rely solely on
buf_pool.mutex, no buf_pool.page_hash latch at all.
The buf_pool.mutex is rather contended in I/O heavy benchmarks,
especially when the workload does not fit in the buffer pool.
The first attempt to alleviate the contention was the
buf_pool_t::mutex split in
commit 4ed7082eef
which introduced buf_block_t::mutex, which we are now removing.
Later, multiple instances of buf_pool_t were introduced
in commit c18084f71b
and recently removed by us in
commit 1a6f708ec5 (MDEV-15058).
UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool
related debugging in otherwise non-debug builds has not been used
for years. Instead, we have been using UNIV_DEBUG, which is enabled
in CMAKE_BUILD_TYPE=Debug.
buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on
std::atomic and the buf_pool.page_hash latches, and in some cases
depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before.
We must always release buf_block_t::lock before invoking
unfix() or io_unfix(), to prevent a glitch where a block that was
added to the buf_pool.free list would apper X-latched. See
commit c5883debd6 how this glitch
was finally caught in a debug environment.
We move some buf_pool_t::page_hash specific code from the
ha and hash modules to buf_pool, for improved readability.
buf_pool_t::close(): Assert that all blocks are clean, except
on aborted startup or crash-like shutdown.
buf_pool_t::validate(): No longer attempt to validate
n_flush[] against the number of BUF_IO_WRITE fixed blocks,
because buf_page_t::flush_type no longer exists.
buf_pool_t::watch_set(): Replaces buf_pool_watch_set().
Reduce mutex contention by separating the buf_pool.watch[]
allocation and the insert into buf_pool.page_hash.
buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a
buf_pool.page_hash latch.
Replaces and extends buf_page_hash_lock_s_confirm()
and buf_page_hash_lock_x_confirm().
buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES.
buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads:
Use Atomic_counter.
buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out().
buf_pool_t::LRU_remove(): Remove a block from the LRU list
and return its predecessor. Incorporates buf_LRU_adjust_hp(),
which was removed.
buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(),
for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by
BTR_DELETE_OP (purge), which is never invoked on temporary tables.
buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments.
buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition.
buf_LRU_free_page(): Clarify the function comment.
buf_flush_check_neighbor(), buf_flush_check_neighbors():
Rewrite the construction of the page hash range. We will hold
the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64)
consecutive lookups of buf_pool.page_hash.
buf_flush_page_and_try_neighbors(): Remove.
Merge to its only callers, and remove redundant operations in
buf_flush_LRU_list_batch().
buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite.
Do not acquire buf_pool.mutex, and iterate directly with page_id_t.
ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined
and avoids any loops.
fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove.
buf_flush_page(): Add a fil_space_t* parameter. Minimize the
buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated
atomically with the io_fix, and we will protect most buf_block_t
fields with buf_block_t::lock. The function
buf_flush_write_block_low() is removed and merged here.
buf_page_init_for_read(): Use static linkage. Initialize the newly
allocated block and acquire the exclusive buf_block_t::lock while not
holding any mutex.
IORequest::IORequest(): Remove the body. We only need to invoke
set_punch_hole() in buf_flush_page() and nowhere else.
buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type.
This field is only used during a fil_io() call.
That function already takes IORequest as a parameter, so we had
better introduce for the rarely changing field.
buf_block_t::init(): Replaces buf_page_init().
buf_page_t::init(): Replaces buf_page_init_low().
buf_block_t::initialise(): Initialise many fields, but
keep the buf_page_t::state(). Both buf_pool_t::validate() and
buf_page_optimistic_get() requires that buf_page_t::in_file()
be protected atomically with buf_page_t::in_page_hash
and buf_page_t::in_LRU_list.
buf_page_optimistic_get(): Now that buf_block_t::mutex
no longer exists, we must check buf_page_t::io_fix()
after acquiring the buf_pool.page_hash lock, to detect
whether buf_page_init_for_read() has been initiated.
We will also check the io_fix() before acquiring hash_lock
in order to avoid unnecessary computation.
The field buf_block_t::modify_clock (protected by buf_block_t::lock)
allows buf_page_optimistic_get() to validate the block.
buf_page_t::real_size: Remove. It was only used while flushing
pages of page_compressed tables.
buf_page_encrypt(): Add an output parameter that allows us ot eliminate
buf_page_t::real_size. Replace a condition with debug assertion.
buf_page_should_punch_hole(): Remove.
buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch().
Add the parameter size (to replace buf_page_t::real_size).
buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page().
Add the parameter size (to replace buf_page_t::real_size).
fil_system_t::detach(): Replaces fil_space_detach().
Ensure that fil_validate() will not be violated even if
fil_system.mutex is released and reacquired.
fil_node_t::complete_io(): Renamed from fil_node_complete_io().
fil_node_t::close_to_free(): Replaces fil_node_close_to_free().
Avoid invoking fil_node_t::close() because fil_system.n_open
has already been decremented in fil_space_t::detach().
BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY.
BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE,
and distinguish dirty pages by buf_page_t::oldest_modification().
BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead.
This state was only being used for buf_page_t that are in
buf_pool.watch.
buf_pool_t::watch[]: Remove pointer indirection.
buf_page_t::in_flush_list: Remove. It was set if and only if
buf_page_t::oldest_modification() is nonzero.
buf_page_decrypt_after_read(), buf_corrupt_page_release(),
buf_page_check_corrupt(): Change the const fil_space_t* parameter
to const fil_node_t& so that we can report the correct file name.
buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function.
buf_page_io_complete(): Split to buf_page_read_complete() and
buf_page_write_complete().
buf_dblwr_t::in_use: Remove.
buf_dblwr_t::buf_block_array: Add IORequest::flush_t.
buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of
os_aio_wait_until_no_pending_writes().
buf_flush_write_complete(): Declare static, not global.
Add the parameter IORequest::flush_t.
buf_flush_freed_page(): Simplify the code.
recv_sys_t::flush_lru: Renamed from flush_type and changed to bool.
fil_read(), fil_write(): Replaced with direct use of fil_io().
fil_buffering_disabled(): Remove. Check srv_file_flush_method directly.
fil_mutex_enter_and_prepare_for_io(): Return the resolved
fil_space_t* to avoid a duplicated lookup in the caller.
fil_report_invalid_page_access(): Clean up the parameters.
fil_io(): Return fil_io_t, which comprises fil_node_t and error code.
Always invoke fil_space_t::acquire_for_io() and let either the
sync=true caller or fil_aio_callback() invoke
fil_space_t::release_for_io().
fil_aio_callback(): Rewrite to replace buf_page_io_complete().
fil_check_pending_operations(): Remove a parameter, and remove some
redundant lookups.
fil_node_close_to_free(): Wait for n_pending==0. Because we no longer
do an extra lookup of the tablespace between fil_io() and the
completion of the operation, we must give fil_node_t::complete_io() a
chance to decrement the counter.
fil_close_tablespace(): Remove unused parameter trx, and document
that this is only invoked during the error handling of IMPORT TABLESPACE.
row_import_discard_changes(): Merged with the only caller,
row_import_cleanup(). Do not lock up the data dictionary while
invoking fil_close_tablespace().
logs_empty_and_mark_files_at_shutdown(): Do not invoke
fil_close_all_files(), to avoid a !needs_flush assertion failure
on fil_node_t::close().
innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files().
fil_close_all_files(): Invoke fil_flush_file_spaces()
to ensure proper durability.
thread_pool::unbind(): Fix a crash that would occur on Windows
after srv_thread_pool->disable_aio() and os_file_close().
This fix was submitted by Vladislav Vaintroub.
Thanks to Matthias Leich and Axel Schwenke for extensive testing,
Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
Introduce a new ATTRIBUTE_NOINLINE to
ib::logger member functions, and add UNIV_UNLIKELY hints to callers.
Also, remove some crash reporting output. If needed, the
information will be available using debugging tools.
Furthermore, remove some fts_enable_diag_print output that included
indexed words in raw form. The code seemed to assume that words are
NUL-terminated byte strings. It is not clear whether a NUL terminator
is always guaranteed to be present. Also, UCS2 or UTF-16 strings would
typically contain many NUL bytes.
Existing implementation used my_checksum (from mysys)
for calculating table checksum and binlog checksum.
This implementation was optimized for powerpc only and lacked
SIMD implementation for x86 (using clmul) and ARM
(using ACLE) instead used zlib-crc32.
mariabackup had its own copy of the crc32 implementation
using hardware optimized implementation only for x86 and lagged
hardware based implementation for powerpc and ARM.
Patch helps unifies all such calls and help aggregate all of them
using an unified interface my_checksum().
Said unification also enables hardware optimized calls for all
architecture viz. x86, ARM, POWERPC.
Default always fallback to zlib crc32.
Thanks to Daniel Black for reviewing, fixing and testing
PowerPC changes. Thanks to Marko and Daniel for early code feedback.
In mysql/mysql-server@17e497bdb7
MySQL 5.6.3 introduced innodb_checksum_algorithm=crc32 and
implemented it for AMD64 using the SSE 4.2 instructions
(incorrectly advertised as "SSE2" in a startup message).
It was not implemented on IA-32 or on Windows.
Since MariaDB 10.2.11 commit 2401d14e6b
we make use of the SSE4.2 CRC-32C instructions on Windows on both IA-32
and AMD64.
Let us be consistent and implement CRC-32C for IA-32 on all
available platforms. GCC 4.8.2 and GCC 4.8.5 complain
"error: PIC register clobbered by 'ebx' in 'asm'"
so we will only enable this code for IA-32 starting with GCC 5.
Also, we will clean up the implementation further after
commit 1312b4ebb6.
has_sse4_2(): Replaces ut_cpuid().
ut_crc32c_8(): Replaces ut_crc32_8_hw().
ut_crc32c_64(): Replaces ut_crc32_64_low_hw(), ut_crc32_64_hw().
ut_crc32_hw(): Rewrite.
ut_crc32c_8_sw(): Replaces ut_crc32_8_sw().
ut_crc32c_64_sw(): Replaces ut_crc32_64_low_sw(), ut_crc32_64_sw().
ut_crc32_sw(): Rewrite. Avoid code bloat and do not unroll the
ut_crc32c_64_sw() loop, because no benefit has been demonstrated.
ut_crc32_init(): Only invoke ut_crc32_slice8_table_init()
if no acceleration is available.
error is logged
The fix is to set flag in ib::error::~error() and check it in
mariabackup.
ib::error::error() is replaced with ib::warn::warn() in
AIO::linux_create_io_ctx() because of two reasons:
1) if we leave it as is, then mariabackup MTR tests will fail with --mem
option, because Linux AIO can not be used on tmpfs,
2) when Linux AIO can not be initialized, InnoDB falls back to simulated
AIO, so such sutiation is not fatal error, it should be treated as warning.
MemorySanitizer (clang -fsanitize=memory) requires that all code
be compiled with instrumentation enabled. The C runtime library
is an exception. Failure to use instrumented libraries will cause
bogus messages about memory being uninitialized.
In WITH_MSAN builds, we must avoid calling getservbyname(),
because even though it is a standard library function, it is
not instrumented, not even in clang 10.
The following cmake options were tested:
-DCMAKE_C_FLAGS='-march=native -O2'
-DCMAKE_CXX_FLAGS='-stdlib=libc++ -march=native -O2'
-DWITH_EMBEDDED_SERVER=OFF -DWITH_UNIT_TESTS=OFF -DCMAKE_BUILD_TYPE=Debug
-DWITH_INNODB_{BZIP2,LZ4,LZMA,LZO,SNAPPY}=OFF
-DPLUGIN_{ARCHIVE,TOKUDB,MROONGA,OQGRAPH,ROCKSDB,CONNECT,SPIDER}=NO
-DWITH_SAFEMALLOC=OFF
-DWITH_{ZLIB,SSL,PCRE}=bundled
-DHAVE_LIBAIO_H=0
-DWITH_MSAN=ON
MEM_MAKE_DEFINED(): An alias for VALGRIND_MAKE_MEM_DEFINED()
and in the future, __msan_unpoison().
For now, neither MEM_MAKE_DEFINED() nor MEM_UNDEFINED()
perform any action under MSAN. Enabling them will catch more bugs, but
will also require some more fixes or work-arounds.
Json_writer::add_double(): Work around a frequently occurring
failure in optimizer tests, related to EXPLAIN FORMAT=JSON.
dtoa(): Disable MSAN altogether. For some reason, this function
is triggering a lot of trouble, especially when invoked for
DBUG functions. The MDL default timeout is dd=86400 seconds,
and for some reason it is claimed to be uninitialized.
InnoDB: Define UNIV_DEBUG_VALGRIND also WITH_MSAN.
ut_crc32_8_hw(), ut_crc32_64_low_hw(): Use the compiler built-in
functions instead of inline assembler when building WITH_MSAN.
This will require at least -msse4.2 when building for IA-32 or AMD64.
The inline assembler would not be instrumented, and would thus cause
bogus failures.
Move function ut_crc32_swap_byteorder to a non-x86 #ifdef area.
As its only used in BIGENDIAN, use #ifdefs around
ut_crc32_swap_byteorder.
Travis CI and Debian both include s390x in builds/test, which is big endian.
Fixes commit: 1312b4ebb6
The -Wconversion in GCC seems to be stricter than in clang.
GCC at least since version 4.4.7 issues truncation warnings for
assignments to bitfields, while clang 10 appears to only issue
warnings when the sizes in bytes rounded to the nearest integer
powers of 2 are different.
Before GCC 10.0.0, -Wconversion required more casts and would not
allow some operations, such as x<<=1 or x+=1 on a data type that
is narrower than int.
GCC 5 (but not GCC 4, GCC 6, or any later version) is complaining
about x|=y even when x and y are compatible types that are narrower
than int. Hence, we must rewrite some x|=y as
x=static_cast<byte>(x|y) or similar, or we must disable -Wconversion.
In GCC 6 and later, the warning for assigning wider to bitfields
that are narrower than 8, 16, or 32 bits can be suppressed by
applying a bitwise & with the exact bitmask of the bitfield.
For older GCC, we must disable -Wconversion for GCC 4 or 5 in such
cases.
The bitwise negation operator appears to promote short integers
to a wider type, and hence we must add explicit truncation casts
around them. Microsoft Visual C does not allow a static_cast to
truncate a constant, such as static_cast<byte>(1) truncating int.
Hence, we will use the constructor-style cast byte(~1) for such cases.
This has been tested at least with GCC 4.8.5, 5.4.0, 7.4.0, 9.2.1, 10.0.0,
clang 9.0.1, 10.0.0, and MSVC 14.22.27905 (Microsoft Visual Studio 2019)
on 64-bit and 32-bit targets (IA-32, AMD64, POWER 8, POWER 9, ARMv8).
The ut_crc32() function uses a hard-coded initial CRC-32C value of 0.
Replace it with ut_crc32_low(), which allows to specify the initial
checksum value, and provide an inlined compatibility wrapper ut_crc32().
Also, remove non-inlined wrapper functions on ARMv8 and POWER8,
and remove dead code (the generic implementation) on POWER8.
Note: The original AMD64 instruction set architecture in 2003 only
included SSE2. The CRC-32C instructions are part of the SSE4.2
instruction set extension for IA-32 and AMD64, with first processors
released in November 2007 (using the AMD Barcelona microarchitecture)
and November 2008 (Intel Nehalem microarchiteture). It might be safe
to assume that SSE4.2 is available on all currently used AMD64 based
systems, but we are not taking that step yet.
